The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 11, 2012
Filed:
Jul. 09, 2010
Masahiko Tamura, Ayutthaya, TH;
Toru Momose, Tokyo, JP;
Katsuaki Miyatani, Tokyo, JP;
Tetsuya Nakashima, Tokyo, JP;
Masahiko Tamura, Ayutthaya, TH;
Toru Momose, Tokyo, JP;
Katsuaki Miyatani, Tokyo, JP;
Tetsuya Nakashima, Tokyo, JP;
Asahi Glass Company, Limited, Tokyo, JP;
Abstract
The present invention relates to a method for manufacturing a glass substrate for information recording medium, the method including: a lapping step of lapping a circular glass plate made of an alkali aluminosilicate glass; and a subsequent cerium oxide polishing step of polishing the circular glass plate with a slurry containing a cerium oxide abrasive, in which a difference (SiO−AlO) obtained by subtracting an AlOcontent from an SiOcontent in the alkali aluminosilicate glass is 62% by mole or less; and in which the method further includes: subsequently to the cerium oxide polishing step, a cleaning step of cleaning the circular glass plate with a cleaning liquid having a sulfuric acid concentration of 20% by mass or more and 80% by mass or less and a hydrogen peroxide concentration of 1% by mass or more and 10% by mass or less at a liquid temperature of 50° C. or higher and 100° C. or lower, and after the cleaning step, a finish polishing step of polishing a main surface of the circular glass plate with a slurry containing a colloidal silica abrasive.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile